Precision Ball and Gauge

A world leader in the manufacture of high precision and quality balls

and related products

Reputable

We take pride in our reputation for delivering high quality balls and ball products in a wide variety of materials and tolerance grades.

Precision

Our Quality Control department, using state of the art equipment, rigorously measure and check statistically for compliance with our customers' orders and relevant international standards ISO 3290, AFBMA Standard 10, and Din 5401. Certificates of Calibration or Conformance can be supplied, giving you the peace of mind in knowing these really are balls of the finest quality available today.

Availability

With massive stocks of quality balls from 0.4mm to 100.00mm diameters, we are certain to stock your exact requirements. From our highly organised delivery system to our three day turn around on most special production orders (subject to quantity ordered) .... we offer a service rarely matched by our competitors.

Adaptable

Our flexibility combined with extensive experience of ball finishing allows us to tailor our products and production capabilities to meet any requirement for precision balls.
Whatever your precision ball needs, we have the ability and desire to deliver the right product, on time, everytime.

Ball Specifications

Steel Balls are manufactured to a number
of international standards produced to meet the needs of Bearing manufacturers.
Of these standards, AFBMA 10, ISO 3970, and DIN 5401 are probably
the most common. ISO and DIN are well known organisations,
AFBMA, the "Anti Friction Bearing Manufacturers Association",
is probably less well known, but in relation to ball specifications
is probably the most important, and in general terms all major ball
standards are based on AFBMA 10. DIN 5401 used to be the exception,
but was brought into line with AFBMA 10 in 1993.

The specifications define balls in terms of a series of properties:-

Basic Diameter - The nominal diameter of the ball eg. 10mm

Ball Diameter Variation - The difference between the largest
and smallest diameter measured for a single ball.

Ball mean diameter - The arithmetic mean of the maximum and
minimum diameters measured for the ball.

Lot Mean Diameter - the arithmetic mean of the smallest and
the largest mean ball diameters within the lot.

Lot diameter variation - The difference between the smallest
and the largest mean ball diameters within the lot.

Gauge - The deviation of the lot mean diameter from the nominal
diameter.

Grade - A number by which the properties of the ball are specified.

Specifications

AFBMA Std 10 - Principle Tolerances

Grade

Basic Diameter Tolerance

Ball Diameter Variation

Deviation From Spherical Form

Surface Roughness Ra

Allowable Lot Diameter Variation

3

± 0.75µm

± 0.08µm

± 0.08µm

0.012µm

± 0.13µm

5

± 1.25µm

± 0.13µm

± 0.13µm

0.02µm

± 0.25µm

10

± 1.25µm

± 0.25µm

± 0.25µm

0.025µm

± 0.50µm

15

± 2.50µm

± 0.38µm

± 0.38µm

0.025µm

± 0.75µm

20

± 2.50µm

± 0.50µm

± 0.50µm

0.05µm

± 1.00µm

25

± 2.50µm

± 0.64µm

± 0.64µm

0.05µm

± 1.25µm

40

± 2.50µm

± 1.00µm

± 1.00µm

0.08µm

± 2.00µm

50

± 5.00µm

± 1.25µm

± 1.25µm

0.08µm

± 2.50µm

100

± 12.50µm

± 2.50µm

± 2.50µm

0.125µm

± 5.00µm

200

± 25.00µm

± 5.00µm

± 5.00µm

0.20µm

± 10.0µm

500

± 50.00µm

± 12.5µm

± 12.5µm

not specified

± 25.0µm

1000

± 125µm

± 25µm

± 25µm

not specified

± 50µm

ISO 3290 - Principle Tolerances

Grade

BasicDiameterTolerance

BallDiameterVariationmax.

DeviationFromSphericalFormmax.

SurfaceRoughnessRamax.

LotDiameterVariation max.

3

± 0.75µm

± 0.08µm

± 0.08µm

0.012µm

± 0.13µm

5

± 1.25µm

± 0.13µm

± 0.13µm

0.02µm

± 0.25µm

10

± 1.25µm

± 0.25µm

± 0.25µm

0.025µm

± 0.50µm

15

± 2.50µm

± 0.38µm

± 0.38µm

0.025µm

± 0.75µm

20

± 2.50µm

± 0.50µm

± 0.50µm

0.05µm

± 1.00µm

25

± 2.50µm

± 0.64µm

± 0.64µm

0.05µm

± 1.25µm

40

± 2.50µm

± 1.00µm

± 1.00µm

0.08µm

± 2.00µm

50

± 5.00µm

± 1.25µm

± 1.25µm

0.08µm

± 2.50µm

100

± 12.50µm

± 2.50µm

± 2.50µm

0.125µm

± 5.00µm

200

± 25.00µm

± 5.00µm

± 5.00µm

0.20µm

± 10.0µm

500

± 50.00µm

± 12.5µm

± 12.5µm

not specified

± 25.0µm

1000

± 125µm

± 25µm

± 25µm

not specified

± 50µm

DIN 5401 - Part 1 - Principle Tolerances

Grade

Nominal Size in mm

Basic
Diameter
Tolerance

Deviation
from
Spherical
Form max.

Ball
Diameter
Variation max.

Surface
Roughness
Ra max.

Lot
Diameter
Variation
max.

Over

Up to

G 3

-

12

± 5.32 μm

0.08 μm

0.08 μm

0.010 μm

0.13 μm

G 5

-

12

± 5.63 μm

0.13 μm

0.13 μm

0.014 μm

0.25 μm

G 10

-

25

± 9.75 μm

0.25 μm

0.25 μm

0.020 μm

0.5 μm

G 16

-

25

± 11.4 μm

0.4 μm

0.4 μm

0.025 μm

0.8 μm

G 20

-

30

± 11.5 μm

0.5μm

0.5 μm

0.032 μm

1 μm

G 28

-

50

± 13.7 μm

0.7μm

0.7 μm

0.050 μm

1.4 μm

G 40

-

100

± 19 μm

1 μm

1 μm

0.060 μm

2 μm

G 100

-

150

± 47.5 μm

2.5 μm

2.5 μm

0.125 μm

5 μm

G 200

-

150

± 72.5 μm

5 μm

5 μm

0.200 μm

10 μm

G500

-

25

± 75
μm

25 μm

25 μm

not specified

50 μm

25

50

± 112.5 μm

25 μm

25 μm

not specified

75 μm

50

75

± 150 μm

25 μm

25 μm

not specified

100 μm

75

100

± 187.5 μm

32 μm

32 μm

not specified

125 μm

100

125

± 225 μm

38 μm

38 μm

not specified

150 μm

125

125

± 262.5 μm

44 μm

44 μm

not specified

175 μm

G 600

all sizes

± 200 μm

not specified

not specified

not specified

400 μm

G 700

all sizes

±1000 μm

not specified

not specified

not specified

2000 μm

Note:

Previous versions of DIN 5401 used class rather than grade.
In general terms these classes can be represented by current grades as follows:-

Class I - Grade 10

Class II - &nbspGrade 20

Class III - &nbspGrade 40

Class IV - &nbspGrade 100

Class V - &nbspGrade 500

Class VI - &nbspGrade 600

Class VII - &nbspGrade 700

However, in all cases it is important to confirm the suitability of the new specification for the specific application in which it is to be used

Relevance to non bearing applications

All of the Ball Specifications discussed have been
developed to cover the requirements of the bearing industry. As a result
some aspects of the specifications whilst important to the needs of bearing
manufacture have little relevance to other applications.

For example:

A high precision angular contact bearing may contain 40 or more balls. If
the bearing is to function correctly with minimum run-out, it is essential
that variation in ball size is minimised. For this reason the maximum lot
diameter variation is specified as twice the allowable spherical error 0.5µm
for grade 10. When the same ball is used singly in a check valve this tight
control of size within a lot is unnecessary.

For this reason it is helpful to the requirements of a specific application
in terms of the properties required from the ball, and then look for the
highest grade that will satisfy them.This approach can avoid the specification
of an unnecessarily high grade of ball and by doing so considerably reduce
cost.

Chrome Steel

Specifications:

AISI 52100, 100Cr6, 1.3505, SUJ2, EN31B

Material Composition

Carbon (C) 0.98 - 1.1%

Chrome (Cr) 1.30 - 1.6%

Silicon (Si)0.15 - 0.30%

Manganese (Mn) 0.25 - 0.45%

Hardness

58 to 62 HRC

Density

7.82

Corrosion Resistance

No natural resistence to corrosion, prone to rusting in damp atmosphere.
Care must be taken to avoid moisture in both use and storage.

Special Properties

Availability

Excellent, Available in a wide range of sizes from 0.5mm to 150mm,
although availability is limited for sizes above 75mm.

Applications

Ball Bearings, Valves, Ball Screws

General Information

By far the most used ball material, Chrome steel balls provide the most
cost effective solution for the vast majority of applications

Stainless Steel

Specification

AISI 440C

Material
Composition

Carbon (C) 0.95 - 1.2%

Chrome (Cr) 16.0 - 18.0%

Silicon (Si) < 1.00%

Manganese < 1.00%

Molybdenum <1.00%

Hardness

56 to 60 HRC

Corrosion
Resistance

No natural resistence
to corrosion, prone to rusting in damp atmosphere. Care must be
taken to avoid moisture in both use and storage.

Special
Properties

Provides a good combination
of corrosion resistance with hardness, at an affordable price

Availability

Good

Available in a fair
range of sizes from 0.5mm to 50mm, although availability is limited
for sizes above 30mm.

An Austenitic stainless
steel, 304 provides a high degree of corrosion resistance. However,
its low hardness can provide problems if loadings are high, and
balls are easilydamaged.

Ceramic - Silicon Nitride

Of all the engineering ceramics so far developed, silicon nitride offers
by far the best combination of properties for most applications.
Its hardness, combined with toughness allows use in many situations
where conventional ball materials fail, or have unacceptably short life.
Its increasing use for high speed bearing applications and resulted
in significant cost reduction such that it can now provide a cost effective
solution for an ever increasing range of problems.

Types:

Various Types are produced, but for ball production
material should be Hot Isostatically Pressed.

Material
Composition

Silicon Nitride with either Yttria or Magnesia.
Material producers include Toshiba, and Norton Abrasives.

Hardness

Typically 1500 to 1600
Hv5

Corrosion
Resistance

Extremely Good Resistance
to most chemical environments.

Density:

~3.2

Special
Properties

Low mass can significantly
reduce forces and inertia in high speed applications.
Hardness is retained to above 1100 degrees Celsius.
Low wear rates in rolling contact with steel.
High toughness.

Widely regarded as the
most significant of the engineering ceramics, Silicon Nitride
is being used in an ever increasing number of applications where
it unique combination of hardness, low mass provide significant
performance advantages.

Cost has decreased significantly
over the last 5 years, to the extent that Silicon Nitride is becoming
a cost effective option for many applications.

Ceramic - Alumina

Type:

Fused Ceramic

Material
Composition

Balls are
produced in a number of diferent materials with purities ranging
from 98.5% to 99.999%

Zirconia balls are used
across a wide range of chemical process aplications, and are extensively
used in oil well pumps. They offer long life in arduous environments.

Tungsten Carbide - Cobalt binder

Specifications:

ISO K10 and K20 are most
common

Material Composition

Typical Material composition
is

6% Cobalt

94% Tungsten Carbide

But other compositions are available with Cobalt content up to
25%. Hardness reduces and toughness increases with increasing cobalt
content.

Hardness

1500 to 1600 HV

Corrosion Resistance

Cobalt binder material
is reasonably resistant to corrosion. The Cobalt binder will corrode
in contact with water, but the effect is largely cosmetic in that
the balls loose their polished appearance, with little effect
on performance.

De-ionised water does
pose a more severe problem, as it can tend to promote 'leeching'
of Cobalt from the binder.

Erosion of the binder
can be a problem when in contact with abrasive particles as may
occur in some valve and pump applications.

Special Properties

Hardness if retained
to approx. 800 degrees Celsius. Balls can be brazes to steel stems
to allow mounting, or hole may be produced by spark erosion.

Availability

Balls are made in a wide
range of sizes from 0.5mm to 50mm and can be made in larger sizes.

Cobalt Binder Tungsten
Carbide is in many ways an ideal material for ball production. Its
hardness and stiffness allows the production of extremely accurate
balls, with very fine control of final size. The material is extremely
stable and these properties make Tungsten Carbide Balls and ideal
choice for reference standards in metrology. Equally, the same properties
make the balls and ideal choice for all applications where wear
rates need to be low.

Tungsten Carbide - Nickel binder

Specifications:

Various, dependent upon
manufacturer

Material Composition

Typical Marerial composition

8 to 10% Nickel (Ni)

90 to 92% Tungsten Carbide (WC)

Some types have Chromium Cardide content to improve corrosion
resistence.

Hardness

Typically 1250 to 1350
HV

Corrosion Resistance

Generally good, and considerably
improved over Cobalt binder material. Nickel Binder Tungsten Carbide
can often be used in a range of chemically agressive environments,
where they offer a significant cost/performace advantage.

Nickel Binder Tungsten
Carbide offers an attractive package of properties for a range of
common industrial applications. It can be succesfully use in many
aggressive environments where it offers performance simmilar to
that of ceramics without some of the attendant difficulties, often
at a significant cost advantage.

Calibrated Master Ball Sets

Each individual set can be supplied with or without its own wooden display case and certificate of calibration.

These are the ultimate ball sets for total accuracy.

l
All Ball Sets available in Grade 10 or 25.

l Manufactured in Tungsten Carbide of hardened Stainless Steel.l Supplied in an attractive solid ash case.l Available in Standard sets of

1mm to 25mm in 1mm increments.

1/32 inch to 1 inch

To Customer specification

l All sets can be supplied with a certificate of Calibration which lists the actual diameter for each balls.l In house (ISO 9002) Certificates supplied with each set.l Certificates traceable to NIST or NAMAS available on request.

Ball Ended Plug Gauges

Gauges are available double or single ended with Wire type handles.

Applications:

General Bore Gauging, Checking Radii, Thread and Gear Measurement.

Advantages:Gauging is carried using a single ball diameter, and is correct irrespective of gauge alignment allowing rapid in-process
checking without the risk of jammed or broken gauges.

Fixture and Checking Balls

Tungsten Carbide and hardened Stainless Steel Balls are widely used to provide locations and position reference
for both manufacturing tooling and for metrology. Tungsten carbide has the advantage of high hardness 1500 - 1600 Hv,
and a low coeficient of expansion.

Stainless Steel offers the same dimensional accuracy, and has a coefficient of expansion
which matches most steels. It does require greater care in handling, but is prefered in some metrology and fixturing applications.

Examples shown are of our standard types, which are available in a range of sizes and configurations.

Additionally, we frequently manufacture to customers drawings and specifications.

Custom Made Products

Balls on Shafts, Stems, or Wires.
For handling or identification purposes, having a ball attached to a stem
or wire of some form can greatly simplify the use of the ball. In measurement
applications, particularly if a range of similar size balls are used the
ability to identify size visible can be of great advantage

Modified Balls
Half or part balls, Balls with through or blind holes. Balls with internal
threads, or flats. In many instances where a spherical or partially spherical
surface is required, manufacture from all ball offers significant advantages
in terms of accuracy or cost.

Ballizing Balls
Ballizing provides a simple method of producing tightly controlled hole
tolerances at very low cost. In practice ball of the appropriate size
is pressed through a pre-machined bore causing plastic deformation to
occur in the bore wall. Elastic recovery then takes place, and produces
the final the final hole size.

The Daily Grind - Perpetual Motion??

Materials

Ceramic Balls

Modern Engineering Ceramics are being used in increasing volumes throughout manufacturing industry. They
offer a range of interesting and often valuable properties are difficult or indeed impossible to
achieve with other materials. The nature of these materials, particularly the combination of hardness
and stiffness makes them ideally suited to the production of high precision balls.
Three materials have attracted particular attention for ball manufacture:-

Silicon Nitride

Combining hardness and toughness with low mass, Silicon Nitride offers significant advantages in high speed bearing
applications, and for these reasons it is finding increaing application in arduous bearing applications such as machine
tool spindles and vacuum pumps. Increasing use and production volumes have dramatically considerably reduced the once astromomic cost of
the material so that silicon nitride balls can offer extremely cost effective solutions to common industrial problems.

Alumina (Aluminium Oxide)

Alumina is used in 2 forms for ball production.

Fused Ceramic

Alumina balls range in colour from almost white to a creamy yellow colour. The material is very harder, but less tough than
either silicon nitride or alumina. Structurally the balls perform well, but are prone to localised surface damage, which
ultimtly promotes failure. Alumina balls are wideley used medical applications particularly for replacement hip joints, and
in valves and pumps for agressive chemical environments.

Single Crystal - Synthetic Ruby and Saphire

Single Crystal alumina is widely use for contact point for measuring equipment, and in this application provides good
wear resistance at an effective price. Saphire balls are clear, perhaps with a blue tint, and are far less common than
ruby which range in colour from almost clear to dark red, Balls are often supplied with drilled holes for mounting purposes.

Zirconia (Zirconium Oxide)

Zirconia in its partially stabilised form offers a number of useful properties. It can withstand very high temperatures
without deterioration, it has a similar rate of thermal expansion to steel, it has a high toughness, and it is
relatively inexpensisive. It does have a tendency to porosity, and which can prompt failure in some circumstances, and tends
to make it unsuitable for high stress applications, but it is widely used in pumps and valves for agressive environments, and
for measurement satndards.

Balls shapes are made in other ceramic materials, usually for very specific applications. Cubic Zirconia balls
are used as lenses in some very specialised fibre optic systems, but they are not generally available.
Silicon Carbide is interesting for some applications, particularly its "conductive" forms, but its inherently
low toughness makes ball production difficult and consequently expensive.

Steel Balls

Off all of the precision balls produced, probably more than 90% are steel, and the bulk of these are chrome steel.
The scale of production is such that steel balls provide the most cost effective solution for all applications where
their properties are appropriate.

Steel

Chrome Steel

(AISI 52100, 100cr6 SUJ2, EN31B, 1.3505)

Stainless Steel

440C

420

316

304

Other Steels

High Speed Steel

Carbon Steel

Mild Steel

Tungsten Carbide Balls

Tungsten Carbide or more correctly Cemented Tungsten Carbide is strictly a "cermet" - ceramic metal combination,
where particles of ceramic, tungsten carbide, are bonded together in a metal matrix. Originally produced as a cutting tool
material - a market which it now dominates, Tungsten Carbide is widely used where hardness and high wear resistance is
required. Variation in the binder percentage, and the size of the carbide particles allows fine control over the properties
of the material, hardness reducing and toughness increasing with increaing binder content.
The binder material also contributes to the overall properties of the material. The two most common types are:-

Cobalt Binder Tungsten Carbide

By far the most common form of Tungsten Carbide, Cobalt binder material is made in a range of compositions with up to 25%
binder. Balls are generally made of material with a 6% binder content. It is suceptible to corrosion of the cobalt binder,
particularly in contact with water, and although this rarely results in structural falure it can cause severe degradation
of the ball surface.

Nickel Binder Tungsten Carbide

Nickel binder Tungsten Carbide is far less common than cobalt binder material, is not made in same range of composition, and tends to be slightly softer.
However. it offers significantly better resitance to corrosion. It is particularly usefull in valve and pump applications,
and it performs well in more agressive chemical environments.

Other Materials

Apart from the materials discussed separately, balls are made as standard in a variety of other materials. Some
of the more common materials are listed here:-

Stellite (Cobalt Chrome)

Stellite balls are made in a small range of sizes, and are used in a number of specific applications.
The material provides a useful combination of properties in that it is metalic, conductive, non magnetic, has good hot hardness
and shock resistence and corrosion resistence. Where precision balls are required with combinations of these properties,
Stellite often offers the most effective solution.

Titanium

Used for a number of medical applications, body jewelry, and some industrial applications, titanium balls are available
in a small range of sizes. The low hardness ~40 HRC, limits the precision to which balls can be made, but where other
properties of titanium are necessary they can often be used effectively. Titanium balls can be supplied in medically approved grades,
and for decorative applications can be supplied eith coloured surface.

Brass & Bronze

Brass and Bronze balls are made in a good range of sizes, and are often used in gas applications where non sparking
materials are specified. They are also used in decorative applications.

Copper

Aluminium

Glass

Plastics

Nylon

Delrin

PTFE (Teflon)

Phenolic

BUNA

Polypropylene

Rubber

Terms and Conditions

Payment

Payment for orders is due within 30 days of our invoice. We accept most credit and debit cards and bank transfers. Custom manufactured items are not returnable. Terms are subject to change without notice.

FAQs

How thick is the case hardening on Chrome Steel Balls ?

Chrome Steel Balls are through hardened, case hardening is only used on
carbon steel balls.

What are Standard Sizes, I always seem to have trouble obtaining 13mm
steel balls quickly ?

Standard Sizes are no more those sizes that are made in large volume. In smaller
sizes these will include whole and half millimeter, but as sizes increase half and then whole millimeter sizes become less common.
The reason is simply that bearing manufacturers use what are really imperial sizes, 3.969mm, 5.556mm, 7.144mm, 12.7mm etc

I need to use a ball in a valve at 400C. Steel and TC wont
work and ceramics are to brittle, what can I do.

Have you tried Ceramics ? Modern Engineering Ceramics are well suited to
these sorts of application and in most circumstances are unlikely to fail. The materials are "brittle", as is cast iron,
but the forces required to cause failure would cause similar failures in most other materials, including steel.

Hardness

Hardness Conversion Chart

Tensile Strength (N/mm2)

Hardness Vickers

Hardness Brinell*

HRB

HRF

HRC

HRA

770

240

228

98.1

114.3

20.3

60.7

785

245

233

21.3

61.2

800

250

238

99.5

115.1

22.2

61.6

820

255

242

23.1

62.0

835

260

247

(101)

24.0

62.4

850

265

252

25.8

62.7

865

270

257

(102)

25.8

63.1

880

275

261

26.4

63.5

900

208

266

(104)

27.1

63.8

915

285

271

27.8

64.2

930

290

276

(105)

28.5

64.5

950

295

280

29.2

64.8

965

300

285

29.8

65.2

995

310

295

31.0

65.8

1030

320

304

32.2

66.4

1060

330

314

33.3

67.0

1095

340

323

34.4

67.6

1125

350

333

35.5

68.1

1155

360

342

36.6

68.7

1190

370

352

37.7

69.2

1220

380

361

38.8

69.8

1255

390

371

39.8

70.3

1290

400

380

40.8

70.8

1320

410

390

41.8

71.4

1350

420

399

42.7

71.8

1385

430

409

43.6

72.3

1420

440

418

44.5

72.8

1455

450

428

45.3

73.3

1485

460

437

46.1

73.6

1520

470

447

46.9

74.1

1555

480

(456)

47.7

74.5

1595

490

(466)

48.4

74.8

1630

500

(475)

49.1

75.3

1665

510

(485)

49.8

75.7

1700

520

(494)

50.5

76.1

1740

530

(504)

51.1

76.4

1775

540

(513)

51.7

76.7

1810

550

(523)

52.3

77.0

1845

560

(532)

53.0

77.4

1880

570

(542)

53.6

77.8

1920

580

(551)

54.1

78.0

1955

590

(561)

54.7

78.4

1995

600

(570)

55.2

78.6

2030

610

(580)

55.7

78.9

2070

620

(589)

56.3

79.2

2105

630

(599)

56.5

79.5

2145

640

(608)

57.3

79.8

2180

650

(618)

58.7

80.0

660

58.3

80.3

670

58.8

80.6

680

59.2

80.8

690

59.7

81.1

700

60.1

81.3

720

61.0

81.8

740

61.8

82.2

760

62.5

82.6

780

63.3

83.0

800

64.0

83.4

820

64.7

83.8

840

65.3

84.1

860

65.9

84.4

880

66.4

84.7

900

67.0

85.0

920

67.5

85.3

940

68.8

85.6

* calculate from HB = 0.95 x HV

Ball Hardness Corrections for Curvatures

Ball Dia

Rockwell 'C' Readings

(mm)

55

56

57

58

59

60

61

62

63

64

65

3.175

6.1

5.7

5.4

5.1

4.8

4.5

4.2

4.0

3.8

3.6

3.4

3.968

5.6

5.3

5.0

4.7

4.4

4.1

3.8

3.6

3.4

3.2

3.0

4.762

5.1

4.7

4.3

4.0

3.8

3.6

3.4

3.2

3.0

2.8

2.5

5.562

4.6

4.3

4.0

3.7

3.5

3.3

3.1

2.9

2.7

2.5

2.3

6.350

4.1

3.8

3.6

3.3

3.1

2.9

2.7

2.5

2.3

2.1

1.8

7.000

3.7

3.4

3.2

3.0

2.8

2.6

2.4

2.2

2.0

1.8

1.6

7.938

3.1

2.9

2.7

2.6

2.4

2.2

2.0

1.9

1.7

1.5

1.3

8.000

3.1

2.9

2.7

2.6

2.4

2.2

2.0

1.9

1.7

1.5

1.3

9.000

2.7

2.5

2.4

2.2

2.0

1.9

1.7

1.5

1.4

1.2

1.1

9.525

2.5

2.3

2.2

2.0

1.9

1.8

1.6

1.4

1.2

1.1

1.0

10.000

2.4

2.2

2.0

1.9

1.8

1.7

1.5

1.3

1.1

1.0

0.9

11.000

2.1

2.0

1.8

1.7

1.6

1.5

1.3

1.1

0.9

0.8

0.7

12.000

1.9

1.7

1.6

1.5

1.4

1.3

1.1

1.0

0.8

0.7

0.6

12.700

1.8

1.7

1.6

1.5

1.4

1.2

1.0

0.9

0.7

0.6

0.5

13.000

1.8

1.7

1.6

1.5

1.4

1.2

1.0

0.9

0.7

0.6

0.5

14.000

1.6

1.5

1.4

1.3

1.2

1.0

0.9

0.8

0.6

0.5

0.4

15.000

1.5

1.4

1.3

1.2

1.1

0.9

0.8

0.7

0.5

0.4

0.3

15.875

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.5

0.4

0.3

This table is useful for converting Rockwell 'C' readings taken on ball surfaces to equivalent value applicable to flat surfaces. Hardness readings of balls are affected by the curvature and hardness level of the ball. Because of these factors, corrections are necessarily added to the as-read hardness. For ball sizes and hardness values other than shown, values shall be interpolated.

MATERIAL COMPARISON

Material Comparison Chart

Material AISI No.

Equivalents

Hardness HRc

Corrosion Resistance

Air

Water

Food

Liquor

Dilute Acids

Acids

Alkali

Industrial Atmosphere

Salt Air

Wet Steam

Domestic Water

Sea Water

Food Products

Fruit and Veg Juices

Dairy Products

Hot Sulphite

Dye

HCL

H2SO4

HNO3

Phosphoric

H2SO4

HNO3

Phosphoric

Ammonia

Alkaline Salts

Low Carbon AISI 1010-16

Wks 1.0010 ASTM A29 EN32

60 min

3

T

4

4

T

T

T

T

T

T

T

T

T

T

S

T

TS

2

3

High Carbon AISI 1065-85

Wks 1.0616 C85 EN8-9

60 min

3

T

4

4

T

T

T

T

T

T

T

T

T

T

S

T

T

2

3

High Carbon Chrome Alloy AISI 52100

Wks 1.3505 100 CR6 EN31

60/67

3

T

4

4

T

T

T

T

T

T

T

T

T

T

T

1

T

3

2

Stainless Steel AISI 440C

Wks 1.4125 X105 CR M017

57/60

2

3

2

2

T

2

2

3

T

4

T

T

T

T

T

T

T

2

3

Stainless Steel AISI 420

Wks 1.3541 X45 CR13 EN56D

52/55

2

4

1

1

T

3

3

2

T

3

T

T

T

T

T

T

T

2

3

Stainless Steel AISI 302/304

Wks 1.4301 X5 CR NI 1810 EN58E

25/39

2

1

1

1

1

1

2

2

1

4

2

2

2

2

2

2

2

1

1

Stainless Steel AISI 316

Wks 1.4401 Z2 CND17.12 EN518J

25/39

2

1

1

1

1

1

1

1

2

4

T

2

1

2

1

1

1

1

2

Numbers indicate order of preference

1 = Excellent

2= Good

T = Will not withstand conditions

3 = Fair

S = Satisfactory only over 75% concentration

4 = Poor

MEASUREMENT CONVERSIONS

Measurement Conversion

Inch Fractions

Inch Decimals

Metric(mm)

Weight 1000 balls (kg)

Approximate Qty per Litre

Inch Fractions

Inch Decimals

Metric(mm)

Weight 1000 balls (kg)

1/64

.0156

0.397

.00026

-

-

.7480

19.000

27.98

-

.0197

0.500

.00051

-

3/4

.7500

19.050

28.20

1/32

.0312

0.794

.00210

2,100,000

25/32

.7812

19.844

31.87

-

.0394

1.000

.00407

1,210,000

-

.7874

20.000

32.63

3/64

.0469

1.190

.00688

695,000

13/16

.8125

20.637

35.85

-

.0472

1.200

.00704

676,700

-

.8268

21.000

37.77

-

.0590

1.500

.01377

347,000

27/32

.8437

21.431

40.15

1/16

.0625

1.588

.01632

289,000

-

.8661

22.000

43.43

5/64

.0781

1.984

.03187

151,000

7/8

.8750

22.225

44.78

-

.0787

2.000

.0326

146,000

-

.9055

23.000

49.63

3/32

.0937

2.381

.0550

87,000

29/32

.9062

23.019

49.75

-

.0984

2.500

.0638

75,500

15/16

.9375

23.812

55.07

7/64

.1094

2.778

.0875

55,000

-

.9449

24.000

56.39

-

.1181

3.000

.1101

43,000

31/32

.9687

24.606

60.77

1/8

.1250

3.175

.1305

37,000

-

.9842

25.000

63.73

-

.1378

3.500

.1749

27,200

1

1.0000

25.400

66.84

9/64

.1406

3.572

.1859

25,700

-

1.0236

26.000

71.69

5/32

.1562

3.969

.2550

18,700

1.1/16

1.0625

26.987

80.17

-

.1575

4.000

.2610

18,500

-

1.1024

28.000

89.54

11/64

.1719

4.366

.3394

14,300

1.1/8

1.1250

28.575

95.17

-

.1772

4.500

.3716

13,000

-

1.1811

30.000

110.10

3/16

.1875

4.762

.4406

10,700

1.3/16

1.1875

30.162

111.90

-

.1968

5.000

.5099

9,500

1.1/4

1.2500

31.750

130.50

-

.2165

5.500

.6786

7,150

-

1.2598

32.000

133.70

7/32

.2187

5.556

.6996

6,800

1.5/16

1.3125

33.337

151.10

15/64

.2344

5.953

.8605

5,450

-

1.3386

34.000

160.30

-

.2362

6.000

.8810

5,400

1.3/8

1.3750

34.925

173.80

1/4

.2500

6.350

1.044

4,550

-

1.3780

35.000

174.90

-

.2559

6.500

1.120

4,300

-

1.4173

36.000

190.30

17/64

.2656

6.747

1.253

3,800

1.7/16

1.4375

36.512

198.50

-

.2756

7.000

1.399

3,400

-

1.4960

38.000

223.80

9/32

.2812

7.144

1.487

3,250

1.1/2

1.5000

38.100

225.60

-

.2953

7.500

1.721

2,800

1.9/16

1.5625

39.687

255.00

19/64

.2969

7.541

1.749

2,750

-

1.5748

40.000

261.00

5/16

.3125

7.938

2.040

2,350

1.5/8

1.6250

41.275

286.80

-

.3150

8.000

2.088

2,150

1.11/16

1.6875

42.862

321.20

-

.3346

8.500

2.505

1,900

1.3/4

1.7500

44.450

358.20

11/32

.3437

8.731

2.715

1,750

-

1.7716

45.000

371.70

-

.3543

9.000

2.973

1,600

1.13/16

1.8125

46.037

398.00

23/64

.3594

9.128

3.102

1,480

1.7/8

1.8750

47.625

440.60

-

.3740

9.500

3.497

1,350

1.15/16

1.9375

49.212

486.10

3/8

.3750

9.525

3.525

1,300

-

1.9685

50.000

509.90

25/64

.3906

9.922

3.983

1,150

2

2.000

50.800

534.70

-

.3937

10.000

4.079

1,125

2.1/8

2.1250

53.975

641.40

13/32

.4062

10.319

4.481

1,050

-

2.1653

55.000

678.60

-

.4331

11.000

5.429

820

2.1/4

2.2500

57.150

761.30

7/16

.4375

11.112

5.597

810

-

2.3622

60.000

881.00

-

.4528

11.500

6.203

720

2.3/8

2.3750

60.325

895.40

29/64

.4531

11.590

6.219

720

2.1/2

2.5000

63.500

1044.40

15/32

.4687

11.906

6.884

620

-

2.5590

65.000

1120.10

-

.4724

12.000

7.048

615

2.5/8

2.6250

66.675

1209.00

31/64

.4844

12.303

7.596

610

2.3/4

2.7500

69.850

1390.10

1/2

.5000

12.700

8.355

550

-

2.7559

70.000

1484.70

-

.5118

13.000

8.961

490

2.7/8

2.8750

73.025

1588.40

17/32

.5312

13.494

10.02

450

-

2.9528

75.000

1720.70

-

.5512

14.000

11.19

410

3

3.000

76.200

1804.70

9/16

.5625

14.288

11.90

380

3.1/8

3.1250

79.375

2039.80

-

.5905

15.000

13.77

325

-

3.1500

80.000

2088.30

19/32

.5937

15.081

13.99

320

3.1/4

3.2500

82.550

2294.40

5/8

.6250

15.875

16.32

300

-

3.3464

85.000

2530.90

-

.6299

16.000

16.70

275

3.1/2

3.5000

88.900

2865.70

21/32

.6562

16.669

18.89

240

-

3.5433

90.000

2993.40

-

.6693

17.000

20.04

230

-

3.7401

95.000

3521.10

11/16

.6785

17.462

21.72

205

3.3/4

3.7500

95.250

3524.70

-

.7087

18.000

23.79

190

-

3.9370

100.000

4078.80

23/32

27187

18.256

24.82

180

4

4.000

101.600

4277.70

The weights shown are based on Chrome Alloy Steel balls.
Approximate weights for other materials can be obtained by multiplying the weight per 1000 balls by the following figures:-

Carbon Steel

1.004

Stainless Steel AISI 420/440

0.979

Stainless Steel AISI 302/304

1.011

Stainless Steel AISI 316

1.025

Brass

1.074

Tungsten Carbide

1.907

GRADES

ISO 3290

Grade

Ball Dia. Variation (µm)

Deviation from Spherical Form (µm)

Surface Roughness (µm)

Lot Dia. Variation (µm)

Gauge Interval (µm)

Preferred Gauge (µm)

Subgauge Interval (µm)

Subgauge (µm)

G3

0.08

0.08

0.010

0.13

0.5

-5...-0.5 0 +0.5...+5

0.1

-0.2,-0.1, 0, +0.1,+0.2

G5

0.13

0.13

0.014

0.25

1

-5...-1 0 +1...+5

0.2

-0.4,-0.2, 0, +0.2,+0.4

G10

0.25

0.25

0.020

0.5

1

-9...-1 0 +1...+9

0.2

-0.4,-0.2, 0, +0.2,+0.4

G16

0.4

0.4

0.025

0.8

2

-10...-2 0 +2...+10

0.4

-0.8,-0.4 0, +0.4,+0.8

G20

0.5

0.5

0.032

1

2

-10...-2 0 +2...+10

0.4

-0.8,-0.4 0, +0.4,+0.8

G24

0.6

0.6

0.040

1.2

2

-12...-2 0 +2...+12

0.4

-0.8,-0.4 0, +0.4,+0.8

G28

0.7

0.7

0.050

1.4

2

-12...-2 0 +2...+12

0.4

-0.8,-0.4 0, +0.4,+0.8

G40

1

1

0.060

2

4

-16...-4 0 +4...+16

0.8

-1.6,-0.8, 0, +0.8,+1.6

G60

1.5

1.5

0.080

3

6

-18...-6 0 +6...+18

1.2

-2.4,-1.2, 0. +1.2,+2.4

G100

2.5

2.5

0.100

5

10

-40...-10 0 +10...+40

2

-4,-2, 0, +2,+4

G200

5

5

0.150

10

15

-60...-15 0 +15...+60

3

-6,-3, 0, +3,+6

Terms and Conditions

Value Added Tax (VAT) at the current rate will be applied to the combined value of goods and postage.

We only process orders once payment has been received.

Returned goods will be credited, pro-rata to the buyers account, but will exclude any postage incurred by the buyer.

Returned goods may be subject to a re-stocking charge.

Privacy

We do not store any personal information on our website.

We do not use 'cookies' to store infomation on your PC about your visit to our website.